1. Industrial Field
The invention relates to an ink-jet recording head using as vibrating means a piezoelectric vibrator in which layers of a piezoelectric material and an electrode material are alternately stacked.
2. Related Art
Ink-jet recording heads in which a pressure is applied to ink in a pressure chamber to eject ink drops through nozzle openings are roughly classified into two types: the thermal jet type in which a heating element is housed in the pressure chamber; and the piezoelectric type in which the pressure chamber is pressed by a piezoelectric vibrator. The latter one has a feature that the deterioration of ink quality does not occur because ink is not heated, and therefore it can be used in a wide variety of applications such as a color printing.
However, an ink-jet recording head of the ink-jet recording head has a problem. Namely, in order to make the piezoelectric vibrator deform in a degree sufficient for producing ink drops, a drive voltage of several hundred volts must be applied to the piezoelectric vibrator, whereby signal transmission lines and circuit components are required to have a high insulation property.
In order to solve this problem, an improved ink-jet recording head is proposed, for example, in Unexamined European Patent Publication No. 0 443 628 A2. In the improved recording head, a piezoelectric vibrator for compressing and expanding a pressure chamber consists of layers of a piezoelectric material and an electrode material which are alternately stacked.
According to the proposed configuration, the driving voltage can be lowered to about 30 volts so that the structures of the driving circuit and power supply means can be simplified.
In the proposed configuration, layers of the two different materials, the piezoelectric material and the electrode material are stacked. This produces a drawback that the strength of the piezoelectric vibrator having such a lamination structure has a lower strength than that of a piezoelectric vibrator having a monolithic piezoelectric vibrator substrate.